When they happened to meet in the hallway at a conference, Jobs started berating Gates for his refusal to do software for NeXT. “When you get a market, I will consider it,” Gates replied. Jobs got angry. “It was a screaming

battle, right in front of everybody,” recalled Adele Goldberg, the Xerox PARC engineer. Jobs insisted that NeXT was the next wave of computing. Gates, as

he often did, got more expressionless as Jobs got more heated. He finally just shook his head and walked away.

Beneath their personal rivalry—and occasional grudging respect—was their basic philosophical difference. Jobs believed in an end-to-end integration of hardware and software, which led him to build a machine that was not

compatible with others. Gates believed in, and profited from, a world in which different companies made machines that were compatible with one another; their hardware ran a standard operating system (Microsoft’s Windows) and

could all use the same software apps (such as Microsoft’s Word and Excel). “His product comes with an interesting feature called incompatibility,” Gates

told the Washington Post. “It doesn’t run any of the existing software. It’s a super-nice computer. I don’t think if I went out to design an incompatible computer I would have done as well as he did.”

At a forum in Cambridge, Massachusetts, in 1989, Jobs and Gates appeared sequentially, laying out their competing worldviews. Jobs spoke about how

new waves come along in the computer industry every few years. Macintosh had launched a revolutionary new approach with the graphical interface; now

NeXT was doing it with object-oriented programming tied to a powerful new machine based on an optical disk. Every major software vendor realized they

had to be part of this new wave, he said, “except Microsoft.” When Gates came up, he reiterated his belief that Jobs’s end-to-end control of the software and

the hardware was destined for failure, just as Apple had failed in competing against the Microsoft Windows standard. “The hardware market and the

software market are separate,” he said. When asked about the great design that could come from Jobs’s approach, Gates gestured to the NeXT prototype that was still